One vertex per element, one color per generator, with an edge from x to x·s.
(1,2,5,4)(3,7,8,6)(9,10,15,14)(11,17,12,16)(13,18,21,22)(19,24,20,23)(25,26,30,28)(27,31,33,34)(29,32,37,36)(35,38,39,40)(1,3,5,8)(2,6,4,7)(9,11,15,12)(10,16,14,17)(13,19,21,20)(18,23,22,24)(27,33)(31,34)(35,39)(38,40)(1,2,5,4)(3,6,8,7)(9,11,15,12)(10,16,14,17)(13,19,21,20)(18,23,22,24)(25,27)(26,31)(28,34)(29,35)(30,33)(32,38)(36,40)(37,39)(9,12,15,11)(10,17,14,16)(13,20,21,19)(18,24,22,23)(1,4,5,2)(3,7,8,6)(9,13)(10,18)(11,19)(12,20)(14,22)(15,21)(16,23)(17,24)(25,28,30,26)(27,34,33,31)(29,32,37,36)(35,38,39,40)(9,14,15,10)(11,17,12,16)(13,18,21,22)(19,23,20,24)(25,29,30,37)(26,32,28,36)(27,35,33,39)(31,38,34,40)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.